.top{
    background: black;
    line-height: 46px;
    text-align: right;
    font-size: 20px;
}
.top a{
    color: white;
}
.nav{
    line-height: 40px;
}
.nav a{
    color: black;
}

.left{
    float: left;
    width: 20%;
    text-align: center;
}
.left img{
    width: 38px;
    height: 38px;
}
.left span{
    vertical-align: 55%;
}
.center{
    width: 60%;
    float: left;
}
.right{
    width: 20%;
    float: left;
}
/*底部超链接，清除浮动、背景色蓝色、文本居中*/
.footer{
    clear: both;
    background: blue;
    text-align: center;
}

/*超链接标签，去除下划线、文本颜色白色*/
a{
    text-decoration: none;
    color: white;
}
a{
    text-decoration: none;
}
a:hover{
    color: red;
}